Circuit breaker lever



Oct. 28, 1952 H, v ELLIQTT 2,616,011

CIRCUIT BREAKER LEVER Filed April 2, 1949 Patented Oct. 28, 1952 CIRCUIT BEEAKER LEVER Harold V. Elliott, Ander son, Ind., assignor to General Motors Corporation, Detroit, Mich., a.

corporation of Delaware Application April 2, 1949, Serial No. 85,172

(Cl. ZOO-166) 6 Claims.

This invention relates to circuit breakers for ignition timer and more particularly levers of the type shown in C. H. Davis, Jr., Reissue Patent No. 19,083, granted February 13, 1934.

An object of this invention is to provide a durable circuit breaker lever which operates at high speed without chattering or rebounding of the contacts. To accomplish this, the present invention provides a circuit breaker lever of novel construction and a method of making it. A blank of thin sheet metal of symmetrical shape having holes bounded by annular flanges at right angles to the plane of the blank is folded on its axis of symmetry to provide two leaves from which the annular flanges extend in alignment to provide a hub portion which receives a bearing bushing. The edges of the leaves are shaped to provide flanges which extend from the hub portion to the other or free end of the lever and which extend at right angles to the planes of the leaves. These flanges, which together with the annular flanges stiften the lever, provide a contact receiving pad at the free end of the lever and a cam follower rubbing block receiving pad intermediate the ends of the lever. A single rivet, which passes through a hole provided by the rubbing block pad and straddles the leaves and is attached thereto, secures to said pad the rubbing block and one end of a leaf spring. Preferably, the rivet is bonded to the leaves by hydrogen brazing in the same operation which braces the contact to the contact pad.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Figs. l to S show the steps of shaping and folding sheet metal to form the lever.

Figs. 9 to 12 show the steps of parts with the lever.

Fig. 13 is drawn to a larger scale than the preceding iigures and show the lever with a rivet attached thereto.

Fig. 14 is a sectional view on line I4--I 4 of Fig. 13.

Fig. 15 shows a side view of the completed lever.

Figs. 16 and 17 are sectional views taken respectively on lines I--l6 and l'l-I'I of Fig. 15.

A blank 20 is punched from thin sheet steel for example .010 thick. The depressions 2l therein are formed as shown in Fig. 2 and holes 22 are punched in these depressions as shown in Fig. 3 thereby providing flanges 23 which are assembling other 2 shaped to form cylindrical projections 24 (Fig. 4) perpendicular to the plane of the blank 2B. The blank 20 is shaped as shown in Fig. 5 and is provided with holes 25. The blank is then folded on its axis of symmetry to provide two leaves 26 which are folded `together to form a stiffening rib and so that the holes 25 are aligned and the cylindrical anges 24 are aligned on axis perpendicular to the planes of the leaves 25. The leaves 28 are shaped as shown in Fig. 8 to provide flanges 21 which extend from the hub of the lever to the tip thereof and include pads on platforms 28 in the same plane and at right angles to the plane of the leaves 26 from which extend flanges 29 at right angles to the portions 28 and parallel to each other and to the planes of the leaves 2E. The flanges 21 continue from the pad portions 28 to ears 30 which provide a pad for receiving a contact disc. The iiange 21 is in part bent diametrically across the holes 25 so that the flanges 28 together provide a hole 3l which includes the two half portions of the holes 25. The other half portions of the holes 25 are shown at 25 in Fig. 13. A rivet 33 is provided with the notch 34 to straddle both leaves 25 and with a bore 35 in its lower end. A rivet 33 is passed through the hole 3l formed of half portions of holes 25 and upwardly as viewed in Fig. 14 so that the notch 34 receives the leaves 2B. The rivet 33 is secured to the leaves 26 by spot welding indicated at 35 in Figs. 13 and 14 to hold it in the desired position which is perpendicular to the flange portions 28.

The assembly of lever and rivet is copper plated and is placed in a iixture which holds the contact disc receiving pads 3U in a horizontal plane facing upwardly. The contact disc, preferably tungsten, is placed upon the pads 33 and this assembly is heated in a hydrogen atmosphere to a temperature sufficient to cause the copper plating to alloy with parts of the assembly and thus form when the assembly is cooled a permanent bond. The contact 40 is bonded to the lever by a layer 4I of copper alloy the thickness of which is somewhat exaggerated in Fig. 15. A copper alloy bond is formed between the rivet 33 and the leaves 26 and some of the copper plating creeps into the hole 3| and substantially fills it so that the rivet is bonded to the flange portions 28 as well as directly to the leaves 25.

A ber bushing 42 is pushed into the flanges 24 (Fig. 16) the edges of which are deformed into grooves 43 provided by the bushing. A rubbing block 44 and a leaf spring 45 having holes for receiving the rivet 33 are assembled as shown in Figs. 15 and 17 and the lower edge of the rivet is deformed at 46 to secure the rubbing block and spring to the lever. The rubbing block ts between the ilanges 29 so that it cannot turn on the rivet. A spring 45 is provided with a notch 4l adapted to be received by a suitable terminal support.

rlhe side flanges 27 which extend from the hub of the lever to the tip thereof contribute materially to the rigidity of the lever and thereby make it possible to make a satisfactory lever of sheet steel having thickness as low as .010 inch. Because thin sheet steel is used, the lever is lighter in weight and therefore will erform satisfactorily at high speed without Contact rebound or chattering, for example, at 2500 R. P. M. ignition timer cam speed or 5000 R. P. M. engine speed. Through the use of a single rivet for attaching the rubbing block and the spring to the lever, durability has been increased.

While the embodiment of the present invention as herein disclosed, constitutes a preferredV form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow What is claimed is as follows:

l. A circuit breaker arm formed from a single sheetoi metal to provide a longitudinally extending stilening rib, a hub, and two flat platform portions, one to support a contact, the ot er a rubbing block, said other platform being apertured to expose the edge of the rib; a stud extending through said aperture and having a forked end straddling the rib to which the stud is welded; and an apertured rubbing block nt.n ting over said stud which is peened over the block to secure the block to the arm.

2. A circuit breaker arm formed from a single sheet of metal to provide a longitudinally ex tending stiffening rib, a hub, and two iiat platform portions, one to support a contact, the other a rubbing block, said other platform being apertured to expose the edge of the rib; a stud extending through said aperture and having a forked end straddling the rib to which the stud is welded; an apertured rubbing block and an apertured leaf spring tting over said stud which is peened over-the spring to secure the spring and block to the arm; and a bearing bushing attached to the hub.

3, A circuit breaker arm formed from a single sheet of metal to provide two integral longitudinally extending leaves, a, hub, and two ilat pads, one to support a contact, the other a rubbing block, said pads being at right angles to the plane of the leaves and said other pad being apertured to expose edges of the leaves; a rivet extending through said aperture and having a forked end straddling the leaves to which the rivet is irremovably attached; and an apertured rubbing block fitting over said rivet which isl upset over the block to secure the block to the arm.

4. A circuit breaker arm formed from a metal blank to provide a longitudinally7 extending stiifening rib, a, hub, and two pads, one to support a contact, the other a rubbing block, said pads being at right angles to the plane of the rib, said other pad being apertured to expose the edge of the rib; spaced parallel iianges associated with said other pad, a, rubbing block supportingy element extending through said aperture and having a bifurcated end straddling the rib to which the element is welded; an apertured rubbing block tted over said element and disposed between said langes whereby the rubbing block is prevented from turning about said element', said element being peened over said block to secure the block to the arm; a bearing bushing attached to said hub.

5. A circuit breaker arm formed from a metal blank to provide a longitudinally extending stiffening rib, a hub comprising oppocitely extending integral annular flanges surroundi f aligned holes, and two pads, each pad inclu Y oppositelyr extending, integral flanges located ,n ther same plane and at right anales to the plane of the rib, one of said pads adapted to support a contact, the other a rubbing block, said other pad being apertured to expose the edge of the rib; a, stud extending through said aperture and having a transverse slot at its inner end straddling the rib to which the stud is irreinovably attached; anapertured rubbing block fitting over the stud which is deformed over the biocl;r to secure the block to the arin; and a bearing bushing retrained within the annular flanges.

6. A circuit breaker arm formed from a single sheet of metal to provide a longitudinally extending stiffening rib, a hub, and a dat platform portion to support a rubbing' block, said platform being provided with an aperture to expose the edge of the rib ;V a stud extending through said aperture and having its inner end provided with a slot whereby it is adapted to straddle the rib; welding material uniting the slotted end of the stud to the rib; an apertured rubbing block tting over the stud which is peened over the block to xedly secure the block to the arm; a contact secured to the rib; and a bearing bush ing carried by the hub.

HAROLD V. ELLIOTT.

REFERENCES CITED The following references are of record in the le of this patent:

Filko Aug. 13, 

